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47 results on '"Wylezinska, Marzena"'

18. A comparison of single‐voxel clinical in vivo hepatic 31P MR spectra acquired at 1.5 and 3.0 Tesla in health and diseased states

Author

Wylezinska, Marzena, primary, Cobbold, Jeremy F.L., additional, Fitzpatrick, Julie, additional, McPhail, Mark J.W., additional, Crossey, Mary M.E., additional, Thomas, Howard C., additional, Hajnal, Joseph V., additional, Vennart, William, additional, Cox, I. Jane, additional, and Taylor‐Robinson, Simon D., additional

Published
2010
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26. Mild Hypothermia after Severe Transient Hypoxia-Ischemia Reduces the Delayed Rise in Cerebral Lactate in the Newborn Piglet

Author

Amess, P N, primary, Penrice, Juliet, additional, Cady, E B, additional, Lorek, Ann, additional, Wylezinska, Marzena, additional, Cooper, C E, additional, D'Souza, Patricia, additional, Tyszczuk, Lidia, additional, Thoresen, Marianne, additional, Edwards, A D, additional, Wyatt, J S, additional, and Reynolds, E O R, additional

Published
1997
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27. Proton Magnetic Resonance Spectroscopy of the Brain during Acute Hypoxia-Ischemia and Delayed Cerebral Energy Failure in the Newborn Piglet

Author

Penrice, Juliet, primary, Lorek, Ann, additional, Cady, E B, additional, Amess, P N, additional, Wylezinska, Marzena, additional, Cooper, C E, additional, D'Souza, Patricia, additional, Brown, G C, additional, Kirkbride, V, additional, Edwards, A D, additional, Wyatt, J S, additional, and Reynolds, E O R, additional

Published
1997
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35. Brain-metabolite transverse relaxation times in magnetic resonance spectroscopy increase as adenosine triphosphate depletes during secondary energy failure following acute hypoxia-ischaemia in the newborn piglet

Author

Cady, Ernest B., primary, Lorek, Ann, additional, Penrice, Juliet, additional, Wylezinska, Marzena, additional, Cooper, Christopher E., additional, Brown, Guy C., additional, Owen-Reece, Huw, additional, Kirkbride, Vincent, additional, Wyatt, John S., additional, Osmund, E., additional, and Reynolds, R., additional

Published
1994
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36. Delayed (“Secondary”) Cerebral Energy Failure after Acute Hypoxia-Ischemia in the Newborn Piglet: Continuous 48-Hour Studies by Phosphorus Magnetic Resonance Spectroscopy

Author

Lorek, Ann, primary, Takei, Y, additional, Cady, E B, additional, Wyatt, J S, additional, Penrice, Juliet, additional, Edwards, A D, additional, Peebles, D, additional, Wylezinska, Marzena, additional, Owen-Reece, H, additional, Kirkbride, V, additional, Cooper, C E, additional, Aldridge, R F, additional, Roth, S C, additional, Brown, G, additional, Delpy, D T, additional, and Reynolds, E O R, additional

Published
1994
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37. 134 CEREBRAL LACTATE AND N-ACETYLASPARTATE/CHOLINE RATIOS AND DELAYED ENERGY FAILURE FOLLOWING ACUTE HYPOXIA-ISCHAEMIA IN THE NEWBORN PIG

Author

Lorek, Ann, primary, Cady, Ernest, additional, Penrice, Juliet, additional, Wyatt, John, additional, Takei, Yukito, additional, Edwards, David, additional, Wylezinska, Marzena, additional, Kirkbride, Vincent, additional, Owen-Reece, Huw, additional, Brown, Guy, additional, Aldridge, Richard, additional, Peebles, Donald, additional, Cooper, Christopher, additional, Roth, Simon, additional, Delpy, David, additional, and Reynolds, Osmund, additional

Published
1994
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39. Polarity-Sensitive Modulation of Cortical Neurotransmitters by Transcranial Stimulation.

Author

Stagg, Charlotte J., Best, Jonathan G., Stephenson, Mary C., O'Shea, Jacinta, Wylezinska, Marzena, Kincses, Z. Tamas, Morris, Peter G., Matthews, Paul M., and Johansen-Berg, Heidi

Subjects
CEREBRAL cortex, NEUROTRANSMITTERS, GABA, NEURAL transmission, EVOKED potentials (Electrophysiology), NEURAL circuitry, MAGNETIC resonance imaging, NEUROSCIENCES
Abstract

Transcranial direct current stimulation (tDCS) modulates cortical excitability and is being used for human studies more frequently. Here we probe the underlying neuronal mechanisms by measuring polarity-specific changes in neurotransmitter concentrations using magnetic resonance spectroscopy (MRS). MRS provides evidence that excitatory (anodal) tDCS causes locally reduced GABA while inhibitory (cathodal) stimulation causes reduced glutamatergic neuronal activity with a highly correlated reduction inGABA,presumably due to the close biochemical relationship between the two neurotransmitters. [ABSTRACT FROM AUTHOR]

Published
2009
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41. Early brain proton magnetic resonance spectroscopy and neonatal neurology related to neurodevelopmental outcome at 1 year in term infants after presumed hypoxic–ischaemic brain injury

Author

*, P N Amess, §, Penrice, Juliet, Wylezinska, Marzena, Lorek, Ann, Townsend, Janice, Wyatt, J S, Amiel-Tison, Claudine, Cady, E B, and Stewart, Ann

Abstract

This study investigated the accuracy of prediction of neurodevelopmental outcome at 1 year using cerebral proton magnetic resonance spectroscopy (MRS) and structured neonatal neurological assessment in term infants after presumed hypoxic–ischaemic brain injury. Eighteen control infants and 28 infants with presumed hypoxic–ischaemic brain injury underwent proton MRS investigation. Studies were carried out as soon as possible after the cerebral insult, most within 48 hours. Infants had an early structured neurological assessment at a median of 19 hours (range 0 hours to 9 days) from the presumed hypoxic–ischaemic insult and a late assessment at a median of 7 days (range 3 to 25 days) during recovery. The maximum cerebral peak–area ratio lactate:N-acetylaspartate measured by proton MRS accurately predicted adverse outcome at 1 year with a specificity of 93% and positive predictive value of 92%. Neurological assessment had a tendency for false-positive predictions. However, both early and late neurological examination can be used as a reliable indicator for a favourable outcome at 1 year having negative predictive values of 100% and 91% respectively.

Published
1999

43. 1H magnetic resonance spectroscopy of the brains of normal infants and after perinatal hypoxia-ischemia

Author

Cady, Ernest B., Lorek, Ann, Penrice, Juliet, Aldridge, Richard, Wylezinska, Marzena, Wyatt, John S., Osmund, E., and Reynolds, R.

Abstract

The aims of this study were to define proton (1H) metabolite peak-area ratios in the brains of normal infants and to investigate abnormalities after perinatal hypoxia-ischemia. Point-resolved spectroscopy (PRESS) data were collected at 2.4 T with an echo time (TE) of 270 ms from 8-ml voxels located in the thalamus or occipito-parietal region. Fourteen normal and 9 asphyxiated infants were studied. The gestational plus postnatal ages (GPA) of these two groups were 31–41 (median 36) and 27–41 (37) weeks, respectively, and the asphyxiated infants were studied aged 0–10 (2) days. Peak-area ratios were determined in the normal infants for choline-containing compounds (Cho), creatine plus phosphocreatine (Cr),N-acetylaspartate (NAA) and lactate (Lac). Lactate was detected in all the normal infants and Lac/NAA was higher in the occipito-parietal region than in the thalamus (p<0.005). Lac/NAA decreased with increasing GPA in both the thalamus (p=0.014) and the occipito-parietal region (p=0.033). In six of the nine asphyxiated infants, Lac/NAA was above 95% confidence intervals for either the thalamus and/or the occipito-parietal region. Of these six infants, two died and three were neurologically abnormal aged 2 months, indicating that elevated Lac/NAA after perinatal hypoxia-ischemia may convey a poor prognosis. Propan-l,2-diol (the phenobarbitone injection medium) was detected at ~ 1.1 ppm in three infants.

Published
1994
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45. Myo-inositol metabolism in appropriately grown and growth-restricted fetuses: a proton magnetic resonance spectroscopy study.

Author

Story L, Damodaram MS, Supramaniam V, Allsop JM, Mcguinness A, Patel A, Wylezinska M, Kumar S, and Rutherford MA

Subjects
Astrocytes metabolism, Case-Control Studies, Creatine metabolism, Female, Humans, Hypoxia metabolism, Linear Models, Magnetic Resonance Imaging, Male, Pregnancy, Brain metabolism, Fetal Growth Retardation metabolism, Fetus metabolism, Inositol metabolism
Abstract

Objective: Myo-inositol (Myo-ins) is a marker of neuroglial cells, being present in the astrocytes of brain tissue, but also functions as an osmolyte. Numbers of astrocytes are known to increase following injury to the brain. Growth-restricted fetuses are at increased risk of later neurodevelopmental impairments even in the absence of overt lesions and despite preserved/increased cerebral blood flow. This study aims to investigate brain Myo-ins metabolism in fetuses with intrauterine growth restriction (IUGR) and evidence of cerebral redistribution using magnetic resonance spectroscopy (MRS) at a short echo time., Study Design: Biometry and Doppler assessment of blood flow was assessed using ultrasound in 28 fetuses with IUGR and 47 appropriately grown control subjects. MRI was used to exclude overt brain injury. Proton magnetic resonance spectroscopy of the fetal brain was then performed at an echo time of 42 ms to examine the Myo-ins:Choline (Cho), Myo-ins:Creatine (Cr) and Cho:Cr ratios., Results: No alterations in brain Myo-ins:Cho, Myo-ins:Cr or Cho:Cr ratios were detected between appropriately grown and growth restricted fetuses., Conclusions: IUGR is not associated with a measureable difference in brain myo-inositol ratios. This may be due to the protective effects of preserved cerebral blood flow in growth restriction and comparable astrocyte numbers when compared to controls., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Published
2013
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46. Low GABA concentrations in occipital cortex and anterior cingulate cortex in medication-free, recovered depressed patients.

Author

Bhagwagar Z, Wylezinska M, Jezzard P, Evans J, Boorman E, M Matthews P, and J Cowen P

Subjects
Adult, Case-Control Studies, Creatine metabolism, Depressive Disorder, Major therapy, Down-Regulation, Feasibility Studies, Female, Humans, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy, Male, Middle Aged, Pilot Projects, Prefrontal Cortex metabolism, Recurrence, Remission Induction, Treatment Outcome, Depressive Disorder, Major metabolism, Frontal Lobe metabolism, Occipital Lobe metabolism, gamma-Aminobutyric Acid metabolism
Abstract

Studies using proton magnetic resonance spectroscopy (1H-MRS) indicate that unmedicated, acutely depressed patients have decreased levels of gamma-aminobutyric acid (GABA) in the occipital cortex. The aim of this study was to use 1H-MRS to determine if changes in occipital and frontal cortical GABA levels were present in patients with a history of depression who had recovered and were no longer taking medication. We used 1H-MRS to measure levels of GABA in both occipital cortex and anterior cingulate cortex/prefrontal cortex in medication-free, fully recovered subjects with a history of recurrent unipolar depression. Levels of GABA in both occipital and anterior cingulate cortex were significantly lower in recovered depressed subjects than healthy controls. Our data provide preliminary evidence that a history of recurrent depression is associated with decreased GABA levels in anterior cingulate cortex and occipital cortex. These changes could represent part of the neurobiological vulnerability to recurrent depressive episodes.

Published
2008
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47. Reduction in occipital cortex gamma-aminobutyric acid concentrations in medication-free recovered unipolar depressed and bipolar subjects.

Author

Bhagwagar Z, Wylezinska M, Jezzard P, Evans J, Ashworth F, Sule A, Matthews PM, and Cowen PJ

Subjects
Adult, Aged, Analysis of Variance, Aspartic Acid analogs & derivatives, Aspartic Acid metabolism, Female, Glutamic Acid metabolism, Glutamine metabolism, Humans, Magnetic Resonance Spectroscopy, Male, Matched-Pair Analysis, Middle Aged, Reference Values, Bipolar Disorder metabolism, Brain Mapping, Depressive Disorder metabolism, Occipital Lobe metabolism, gamma-Aminobutyric Acid metabolism
Abstract

Background: Studies using proton magnetic resonance spectroscopy (MRS) have indicated that unmedicated, acutely depressed patients have decreased levels of gamma-aminobutyric acid (GABA) in occipital cortex. Cortical levels of glutamate (Glu) may be increased, although these data are less consistent. The aim of this study was to use MRS to determine whether changes in GABA and Glu levels were present in patients with mood disorders who had recovered and were no longer taking medication., Methods: An [1H]-MRS was used to measure levels of GABA, of the combined concentration of Glu and glutamine (Gln), and of N-acetylaspartate (NAA) in occipital cortex in medication-free, fully recovered subjects with a history of recurrent unipolar depression (n = 15), bipolar disorder (n = 16), and a group of healthy controls (n = 18)., Results: Occipital levels of GABA and NAA were significantly lower in recovered depressed and bipolar subjects than in healthy controls, whereas Glu +Gln concentrations were higher., Conclusions: Our data suggest that recovered unmedicated subjects with a history of mood disorder have changes in cortical concentrations of GABA, NAA, and Glu +Gln. These biochemical abnormalities may be markers of a trait vulnerability to mood disorder, rather than neurochemical correlates of an abnormal mood state.

Published
2007
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